Thermal sensitive paper minimized in release of tailings liable to deposit on thermal head

Abstract

A thermal sensitive paper having a heat sensitive layer containing a color-developing lactone compound and a phenol compound is amazingly lessened in release of tailings liable to deposit on the thermal head of a thermal printer, facsimile or such in the printing operation when a layer containing light calcium carbonate or an oil-absorptive inorganic powdery material is provided between the heat sensitive layer and the support.

What is claimed is: 
     
       1. A thermal sensitive paper comprising a support and a heat sensitive layer containing a color-developing lactone compound and a phenol compound, characterized in that a layer formed from at least 1.0 g/m 2 , of a member of the group consisting of light calcium carbonate, an inorganic powdery material with oil absorption of over 50 ml/100 gr as measured according to JIS K-5101 method and a mixture of said light calcium carbonate and said inorganic powdery material is provided between said support and said heat sensitive layer for preventing deposition of tailings to the thermal head. 
     
     
       2. A thermal sensitive paper of claim 1, wherein the spread of said material for preventing deposition of tailings to the thermal head is within the range of 1.0 to 6 g/m 2 . 
     
     
       3. A thermal sensitive paper of claim 1, wherein the average particle size of light calcium carbonate is within the range of 0.2 to 1.5μ. 
     
     
       4. A thermal sensitive paper of claim 1, wherein the inorganic powdery material is at least one member selected from the group consisting of activated clay, calcined kaolin, aluminum oxide with Al 2  O 3  content of at least 80 weight % and inorganic silicic acid with SiO 2  content of at least 80 weight %. 
     
     
       5. A thermal sensitive paper of claim 1, wherein the heat sensitive layer contains a water-soluble high-molecular adhesive. 
     
     
       6. A thermal sensitive paper according to claim 1 wherein said layer between said support and said heat sensitive layer contains calcium carbonate. 
     
     
       7. A thermal sensitive paper according to claim 1 wherein said layer between said support and said heat sensitive layer contains said inorganic powdery material with oil absorption of over 50 ml/100 gr and is free from light calcium carbonate. 
     
     
       8. A thermal sensitive paper according to claim 7 wherein the spread of said material for preventing deposition of tailings to the thermal head is within the range of 1.0 to 6 g/m 2 . 
     
     
       9. A thermal sensitive paper according to claim 7 wherein the heat sensitive layer contains a water-soluble high molecular weight adhesive. 
     
     
       10. A thermal sensitive paper according to claim 7 wherein the inorganic powdery material is at least one member selected from the group consisting of activated clay, calcined kaolin, aluminum oxide with Al 2  O 3  content of at least 80 weight % and inorganic silicic acid with SiO 2  content of at least 80 weight %. 
     
     
       11. A thermal sensitive paper according to claim 10 wherein said inorganic powdery material is activated clay. 
     
     
       12. A thermal sensitive paper according to claim 10 wherein said inorganic powdery material is aluminum oxide with Al 2  O 3  content of at least 80 weight %. 
     
     
       13. A thermal sensitive paper according to claim 10 wherein said inorganic powdery material is inorganic silicic acid with SiO 2  content of at least 80 weight %. 
     
     
       14. A thermal sensitive paper comprising a support and a heat sensitive layer containing a color-developing lactone compound and a phenol compound, characterized in that a layer formed from at least 1.0 g/m 2 , of a member of the group consisting of light calcium carbonate, calcined kaolin with oil absorption of over 50 ml/100 gr as measured according to JIS K-5101 method and a mixture of said light calcium carbonate and said calcined kaolin is provided between said support and said heat sensitive layer for preventing deposition of tailings to the thermal head.